U.S. Secretary of State John Kerry is urging the new prime minister of Iraq to quickly form a cabinet and fight against Islamist militant rebels who are seizing northern Iraqi towns. 

The rise of Islamic State of Iraq and Syria (ISIS) has engaged Iraq in a fierce battle between ISIS, an extremist Islamic group that aims to create a theocratic Islamic state, and Kurdish peshmerga forces.

ISIS has been seizing major towns in Iraq while also causing a severe humanitarian crisis. The humanitarian situation has deteriorated so quickly that the U.S. intervened in the conflict militarily. 

Monday's nomination of Haider al-Abadi to replace Nouri al-Maliki as Prime Minister gives al-Abadi the opportunity to create a new government in the next 30 days before he officially take office. 

Al-Abadi is the deputy speaker of the Iraqi Parliament and al-Maliki's former aide, according to CNN. 

"We urge him to form a new cabinet as urgently as possible, and the U.S. does stand ready to fully support a new and inclusive Iraqi government," Kerry told reporters at a news conference in Sydney on Tuesday. 

Yet, al-Maliki does not want to give up his position. He appeared Monday with junior members of his party and announced that they would oppose al-Abadi's nomination in court. 

Shiite politician and Iraqi President Fuad Masum nominated al-Abadi for the position on Monday, even though al-Maliki said earlier Monday that he plans on staying in office for a third term. It is not yet known if al-Maliki will use force to keep his position. 

Al-Abadi is supported by senior members of the leading parliamentary coalition, including the Iraqi foreign minister and the Dawa party's spokesman. 

Al-Maliki called the nomination "null and void."

"I say to all of you fighters on the front lines ... the army ... the police ... remain in your places and do not worry or be shaken over the constitutional violation," al-Maliki said. "We will repair the mistake."

Kerry said Tuesday that the U.S. will not send ground troops into Iraq. As of now, American planes are executing airstrikes on ISIS targets in the northern part of Iraq. 

"There will be no reintroduction of American combat forces into Iraq," Kerry said Tuesday. "This is a fight that Iraqis need to join on behalf of Iraq."

The U.S. is also offering economic and military aid to al-Abadi under the new, less sectarian government. The offerings are an inducement to form a new government under al-Abadi. 

"Without any question, we are prepared to consider additional political, economic and security options as Iraq starts to build a new government," Kerry said with the aid "very much calculated to try to stabilize the security situation, expand economic development and strengthen the democratic institutions." 

In addition to airstrikes against the militants, the U.S. has intervened by bringing humanitarian air drops of food and other supplies to besieged civilians. 

Ethnic minorities, such as Kurds, Christians and Yazidis, were forced to flee their homes in the semi-autonomous Kurdish region of Iraq because of ISIS violence. ISIS believes that the non-Sunnis are "infidels" and that they must either convert to their specific form of Islam or die. Ethnic and religious minorities have therefore fled to the mountains to escape ISIS persecution. 

The Pentagon is also helping move equipment and arms to the Kurdish peshmerga forces. 

The Washington Post reported Monday that Washington is also covertly arming the Kurdish forces, but Kerry did not mention that during Tuesday's meeting.